fix(engine): respect formatter line length in Refactorex actions

[gpact]

Fix Refactorex code actions to respect project formatter line_length when rewriting code (for example, Remove pipe).

Refactorex was calling Sourceror.to_string/2 without forwarding line_length from formatter config. As a result, code actions formatted output using Sourceror’s default line_length of 98, even when the project configured a different value.

[doorgan]

Thank you! 💜